352 University of California Publications in Botany [Vol. 9 



57. COMPOSITAE (Sunflower Family) 



Corollas all tubular and regular, or only the marginal ones ligulate. 



Anthers not caudate at base; style branches either truncate or tipped with 

 an appendage. 



Heads discoid; flowers purplish, never yellow 1. Eupatoreae 



Heads radiate (exceptional forms rayless) ; flowers commonly yellow. 

 Style branches of perfect flowers flat, or tipped with a distinct appen- 

 dage; leaves mostly alternate 2. Astereae 



Style branches not flattened, but truncate or appendaged; leaves often 

 opposite. 

 Involucre not scarious, little imbricated. 

 Pappus never capillary. 



Keceptaele chaffy 3. Heliantheae 



Eeceptacle not chaffy 4. Helenieae 



Pappus capillary 5. Senecioneae 



Involucre scarious, well imbricated; pappus, if present, never capillary 



but reduced to a low ring 6. Anthemideae 



Anthers caudate at base; style branches neither truncate nor appendaged; 

 heads discoid; leaves alternate. 

 Anthers short caudate at base, unappendaged at tip; involucral bracts 



scarious or white^ never bristly (in ours) 7. Inuleae 



Anthers long caudate and bearing elongated appendages at the tip; thistle- 

 like 8. Cynareae 



Corollas all ligulate and flowers all perfect; plants with milky juice; leaves 

 alternate 9. Cichoreae 



1. EUPATOREAE 



1. Eupatorium 



2. ASTEREAE 



Pappus of two sorts, the inner of fine and long capillary hairs; the outer of 



very short, setulose hairs and inconspicuous; our species rayless 



2. Chrysopsis 



Pappus of similar, though often unequal, hairs. 

 Eays, if present, always yellow. 

 Heads small and clustered. 



Involucral bracts more or less in vertical rows; our species rayless 



(except C. Bloomeri has 2-4 rays) 3. Chrysothamnus 



Involucral bracts not in vertical rows; heads always rayed —.4. Solidago 

 Heads larger, distinct or loosely aggregated. 



Involucral bracts few, subequal, and erect; pappus whitish or ferru- 



gineous 5. Haplopappus 



Involucral bracts numerous, of different lengths, and with divergent 



tips; pappus deep reddish brown 6. Hazardia 



Rays, if present, never yellow, but white, blue, or reddish. 



Involucral bracts broad, numerous, imbricated in several series; rays broad 



and comparatively few 7. Aster 



Involucral bracts very narrow, fewer, arranged in two rows; rays very 

 narrow and numerous 8. Erigeron 



3. HELIANTHEAE 



Bracts of the involucre in several series, and none of them enclosing or wrapped 

 about the outer achenes; ours large coarse perennial herbs. 

 Ray flowers fertile (our only species whitened with floccose wool) 9. Wyethia 



Ray flower sterile (our only species nearly glabrous and green) 



10. Helianthella 



Bracts of the involucre in a single series, and each enclosing one of the outer 

 achenes; ours small, delicate annuals. 

 Ray achenes laterally compressed, each entirely enclosed by the adjacent 

 involucral bract, which is strongly keeled outwardly 11. Madia 



